There has been continuous movement in carrier industries, particularly with air carriers, to move towards passenger seats, which are lighter, simpler, and easier to manufacture and assemble. Lighter, more compact seats offer improved fuel economy, increase available payload for passengers and luggage, and allow for extra passenger space in existing seating arrangements or opportunities for more compact seating arrangements while maintaining passenger space at current levels. The passenger seat is also a major design feature and the structure that passengers are most often in contact with during travel. As such, there is a simultaneous push for more visually appealing designs and improved ergonomics and passenger comfort.
Traditional passenger seats are manufactured with internal frames that are covered with cushions and outer panels that provide the seating surface. These seats can be heavy, bulky, and complex to manufacture, thus resulting in standardized designs. As a result, extra features typically are added onto the seat structures instead of being integrated for a more seamless, efficient design. Existing seat structures are normally built up from metal tubes, bars, or stampings, which makes it difficult if not impossible to include complex curvatures that provide enhanced support for varying passenger physiologies.
In some cases, it may be desirable to design a seat based on ergonomic concepts and configured to provide adequate support for passengers that fall within the range of the fifth to ninety-fifth statistical percentile for body size or shape. Compound or anatomically designed curvatures to the seat back and head rest may be designed to not only cradle the passenger during lateral loads, but also to provide support and maintain alignment of the head, neck, and spine. The seat pan or bottom may be designed to provide proper hip alignment and maintain pressure on the tuberosity of the ischium without creating pressure points. In certain cases, the seat structure may incorporate suspension cushions with anisotropic properties so that cushioning and support may be varied in different directions to provide optimal support and comfort to the passenger.
In certain cases, the use of a monocoque or semi-monocoque seat back may facilitate the design of a passenger seat that is lighter, simpler to manufacture, more compact, while still providing excellent passenger comfort and support. In monocoque designs, the outer skin is the primary load-bearing structure. Similarly, a semi-monocoque design uses the outer skin as the primary load-bearing structure, but incorporates additional inner bracing to strengthen the component. Monocoque or semi-monocoque seat structures, particularly seat backs, may provide additional design freedom as compared with traditional seat frame constructions. Monocoque or semi-monocoque seat structures allow for more freedom in aesthetic design, more complex curvatures for ergonomic support, and more internal space that may be used for locating tray tables, storage pockets, and internal passenger suspension cushions, which would otherwise be too bulky or impossible to fit to existing seat structures.